Constructing Multifunctional Heterostructure of Fe₂O₃@Ni₃Se₄ Nanotubes

Heterostructures have attracted increasing attention due to their amazing synergetic effects, which may improve the electrochemical properties, such as good electrical/ionic conductivity, electrochemical activity, and mechanical stability. Herein, novel hierarchical Fe₂O₃@Ni₃Se₄ nanotubes are successfully fabricated by a multistep strategy. The nanotubes show length sizes of ≈250–500 nm, diameter sizes of ≈100–150 nm, and wall thicknesses of ≈10 nm. The as-prepared Fe₂O₃@Ni₃Se₄ nanotubes with I_Ni:Fe = 1:10 show excellent Li storage properties (897 mAh g⁻¹ high reversible charge capacity at 0.1 A g⁻¹), good rate performance (440 mAh g⁻¹ at 5 A g⁻¹), and outstanding long-term cycling performance (440 mAh g⁻¹ at 5 A g⁻¹ during the 300th cycle) as an anode material for lithium ion batteries. In addition, the Fe₂O₃@Ni₃Se₄ nanotubes with I_Ni:Fe = 1:10 (the atomic ratio between Ni and Fe) show superior electrocatalytic performance toward the oxygen evolution reaction with an overpotential of only 246 mV at 10 mA cm⁻² and a low Tafel slope of 51 mV dec⁻¹ in 1 m KOH solution.